This invention relates to a heat-developable color photographic material improved in image-storage stability and fog, and a process for forming an image.
Color photographic materials that can obtain simply and speedily an image by carrying out a developing step according to the dry processing with heating are known in the art, and such heat-developable color photographic materials and image-forming processes are described, for example, in Japanese Patent Publications No. 4921/1968 and No. 4924/1968; Shashin Kogaku no Kiso (The Basis of Photographic Engineering), pp.553-555 (published by Corona-sha K. K., 1979); Research Disclosure, the June 1978 issue, pp.9-15 (RD-17029); etc.
Recent years, it is also attempted to evolve heat-developable color photographic materials that can obtain a color image by using various dye providing substances. Among these prior arts, superior from viewpoints of the stability or sharpness of an image and the simpleness or rapidness of processing is the method of obtaining a color image by releasing or forming a diffusible dye by heat development and thereafter transferring the dye. The heat-developable color photographic materials and image-forming process according to this transfer method are described, for example, in Japanese Unexamined Patent Publications No. 12431/1984, No. 159159/1984, No. 181345/1984, No. 229556/1984, No. 2950/1985, No. 52643/1986, No. 61158/1986, No. 61157/1986, No. 180550/1984, No. 132952/1986 and No. 139842/1986, U.S. Pat. No. 4,595,652, U.S. Pat. No. 4,590,154 and U.S. Pat. No. 4,584,267, etc.
However, these known heat-developable color photographic materials have been disadvantageous in the storage stability of an image, particularly in that the white ground portions or the image at low density portions may be stained with lapse of time (i.e., generation of stains) or that the fogging may be highly caused.